Seafoam - bad idea.
Thread Starter
Newbie
Joined: Feb 2018
Posts: 5
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From: Huntington, WV
Year: 2000
Model: Cherokee(XJ)
Engine: 4.0
So I posted a few weeks ago about having trouble with white smoke coming out exhaust and a rough idle the day after I did the neon fuel injector swap. I did reinstall all the injectors as some on here suggested and then still had the same problem. THEN it dawned on me. I believe I put seafoam in the gas tank the night before. I bet that is my problem.
I took a look at the spark plugs, they look pretty charred and gunked up already (and I just changed them weeks ago).
So do you guys think that is the problem (white smoke out of exhaust and rough idle due to sea foam). You think I'm going to have to replace all spark plugs again? Anything else I should do?
I took a look at the spark plugs, they look pretty charred and gunked up already (and I just changed them weeks ago).
So do you guys think that is the problem (white smoke out of exhaust and rough idle due to sea foam). You think I'm going to have to replace all spark plugs again? Anything else I should do?
I'm with Tbone... probably not
Just for reference (generally speaking):
Black smoke- Running rich
White Smoke- Coolant in combustion chamber
Blue Smoke- Oil in Combustion chamber
Are you SURE the white smoke isn't condensation from the first start up of the day/cold weather?
Just for reference (generally speaking):
Black smoke- Running rich
White Smoke- Coolant in combustion chamber
Blue Smoke- Oil in Combustion chamber
Are you SURE the white smoke isn't condensation from the first start up of the day/cold weather?
Thread Starter
Newbie
Joined: Feb 2018
Posts: 5
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From: Huntington, WV
Year: 2000
Model: Cherokee(XJ)
Engine: 4.0
I put a whole can in with the tank almost empty then filled the tank up. The jeep ran great the day I did the injector change. Could tell a real difference. Well worth it. Then the next morning, had trouble starting. A lot of white smoke coming out tailpipe and very rough idle. Takes multiple tries to start the jeep as well. Just can't figure it out.
CF Veteran
Joined: Jun 2016
Posts: 2,138
Likes: 278
From: Santa Clarita California
Year: 2001
Model: Cherokee (XJ)
Engine: 4.0L
Also white steam will come when cold . good combustion will produce water / steam . Does the white smoke go away ? it can be the sea foam cleaning out a lot of carbon .
If you ran the gas tank too low, you could have picked up some garbage from the bottom of the tank or maybe clogged a fuel filter. But in general, sea foam is combustable and I don't suspect it would cause an issue like this. Check your injectors and connections.
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CF Veteran
Joined: Oct 2011
Posts: 1,394
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From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
Sea foam wouldn't cause white smoke (steam) in a full tank of gas. It will only do that when it's put directly into the intake manifold. It's extremely concentrated when done that way.
CF Veteran
Joined: Oct 2011
Posts: 1,394
Likes: 8
From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
I'm assuming you're talking about water absorption. In that case, I would say that it's the water causing the steam, not the Seafoam. 
I think you might be on to something there though, since he mentioned that he ran the tank nearly out...
I think you might be on to something there though, since he mentioned that he ran the tank nearly out...
Last edited by Tbone289; Feb 21, 2018 at 03:40 PM.
Yep, that's what I was thinking, At some point it might have got water in the tank, the sea foam picked it up, and now it is burning off the water along with the sea foam and fuel. I seem to remember this happening quite a bit when we used it in boats. But like you say it's not the sea foam, but what the sea foam may have absorbed.
In reply to your edit... lol I didn't read it again but if he used a gas can to dump any in it the gas can could have been the culprit. It is a very common thing as you know to get water in gas cans.
CF Veteran
Joined: Oct 2011
Posts: 1,394
Likes: 8
From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
Good thinking! That's the most likely scenario proposed so far. Hell, actually it's the only logical scenario proposed so far...
If that is what has happened here, I would say adding the Seafoam was a good idea, not a bad one.
If that is what has happened here, I would say adding the Seafoam was a good idea, not a bad one.
Last edited by Tbone289; Feb 21, 2018 at 03:52 PM.

And I think all the gunk is varnish from the tank and lines.
Last edited by Bugout4x4; Feb 21, 2018 at 03:58 PM.
CF Veteran
Joined: Oct 2011
Posts: 1,394
Likes: 8
From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
You mean a gas can? I thought he was referring to the can of Seafoam. Yeah, I keep my cans sealed tight, and never put ethanol in a storage can if I can avoid it.



